March 4, 2019
Distinct Influence of Coupled Ocean-atmosphere Interactions Mediated by Sea Surface Temperature and Current
서효대 박사님 (Woods Hole Oceanographic Institution)
2019년 3월 5일 (화) 16:00
Ocean boundary current systems are characterized by the energetic surface velocity and vigorous coastal upwelling with a rich filamentary eddy structure. The associated large anomalies and gradients of surface current and SST modify the surface stress, triggering so-called mesoscale air-sea interactions. This presentation will discuss results from high-resolution regional coupled model simulations with a scale-separation of the air-sea coupling, showing that mesoscale air-sea interactions through SST and surface current exert dynamically distinct influences on the energetics of these boundary current systems. Effect of SST-wind coupling is manifested most strongly in the Ekman pumping velocity, which primarily affects the position of the eddy fields but not their amplitude. In contrast, the current-wind coupling substantially reduces the total wind work, thus the mean and eddy kinetic energy. The vorticity-induced Ekman pumping through the current-wind coupling further attenuates the eddy amplitude. Significant time-mean responses in SST and evaporation are found due to the current-wind coupling in the Arabian Sea, suggesting its potential importance to downstream atmospheric monsoon circulation.